Follow-Up of Ovarian Cancer: Correlation Between Imaging Findings and CA 125 Serum Value

Objectives: To assess the correlation between imaging findings and Cancer Antigen (CA) 125 serum value in the follow-up of ovarian cancer. Methods: We included 41 consecutive patients with malignant ovarian epithelial cancer who underwent surgical debulking at our institution (Jan 2014-Dec 2018). Computed Tomography (CT) / Positron Emission Tomography (PET)-CT images obtained during follow-up were reviewed for the presence of disease (yes/no). Imaging findings were compared with the CA 125 serum values at the time of examination. Results: Of the 211 imaging studies, 117 (55.5%) were negative for the presence of disease, whereas 94 (44.5%) were positive. The median CA 125 value was 87 U/mL in patients with positive imaging findings and 10 U/mL in patients with negative ones (Mann-Whitney U test, p<0.0001). Of the 129 examinations performed in patients with normal CA 125 serum value, 110 (85.3%) were negative for disease, whereas 19 (14.7%) were positive; the median CA 125 serum value of the latter were 10 U/mL in patients with negative imaging findings and 23 U/mL in patients with positive ones (Mann-Whitney U test, p<0.0001). Only 3/129(2.3%) patients with normal CA 125 serum value, no CA 125 increasing trend and no clinical suspicion of progression showed positive imaging findings. Conclusion: A strict correlation between CA 125 serum value and imaging finding was observed. Imaging should be avoided in patients with normal CA 125 serum value and no clinical suspicion of disease progression.